Transcription
This enzyme binds to a promoter and synthesizes a complementary RNA strand.
What is RNA polymerase?
This type of RNA carries amino acids to the ribosome during translation
What is tRNA?
This type of mutation changes a single nucleotide but does not alter the amino acid sequence of a protein.
What is a silent mutation?
A scientist discovers a microorganism that lacks a membrane-bound nucleus but contains ribosomes, a plasma membrane, and circular DNA. What type of cell is it?
What is a prokaryotic cell?
These cell junctions prevent solutes from passing between adjacent cells by forming a seal.
What are tight junctions?
This DNA sequence is located upstream of a gene and signals where transcription begins.
What is a promoter?
These three sites on the large ribosomal subunit are responsible for receiving, holding, and releasing tRNA.
What are the A, P, and E sites?
This type of mutation changes an amino acid-coding codon into a stop codon, resulting in premature termination of translation.
What is a nonsense mutation?
A newly discovered microorganism survives in an environment with a pH of 1.5. Based on its environmental adaptations, how would this organism be classified?
What is an acidophile?
These anchoring junctions connect adjacent cells through intermediate filaments, providing mechanical strength to tissues.
What are desmosomes?
These noncoding regions are removed from pre-mRNA during eukaryotic RNA processing.
What are introns?
A tRNA molecule has the anticodon 3′-UAC-5′. This is the corresponding mRNA codon and the amino acid it specifies.
What are AUG and methionine?
This type of epigenetic modification relaxes histones, making DNA more accessible and increasing transcription.
What is histone acetylation?
A researcher discovers that a cell accumulates misfolded proteins in the rough ER, eventually triggering apoptosis. Which cellular response has likely failed?
What is the unfolded protein response (UPR)?
These chemical messengers transmit signals between neurons or from neurons to muscle cells.
What are neurotransmitters?
A DNA template strand has the sequence 3′-TAC GGC ATT-5′. What mRNA sequence will be produced?
What is 5′-AUG CCG UAA-3′?
An mRNA sequence reads 5′-AUG GCU UUU UAA-3′. What amino acid sequence will be produced?
What is methionine–alanine–phenylalanine?
During meiosis, homologous chromosomes fail to separate, producing gametes with abnormal chromosome numbers. What event occurred, and what chromosomal abnormality can result?
What are nondisjunction and aneuploidy?
A cell successfully synthesizes and folds proteins in the rough ER, but the proteins cannot be transported to the Golgi apparatus. What cellular structure is most likely malfunctioning?
What are transport vesicles?
A signaling molecule binds to a cell-surface receptor, activating adenylyl cyclase. Which molecule is converted into cAMP, and what is cAMP's role in the signaling pathway?
What is ATP, and cAMP acts as a second messenger?
A mutation prevents the addition of a 5′ G-cap and a 3′ poly-A tail. What is the most likely consequence?
What is increased mRNA degradation?
A mutation prevents empty tRNA molecules from leaving the ribosome after their amino acids have been added to the polypeptide. Which ribosomal site is affected?
What is the E site?
A researcher observes that two nonhomologous chromosomes have exchanged segments, but the total number of chromosomes remains unchanged. What type of chromosomal mutation has occurred?
What is a translocation?
A researcher observes that chromosomes fail to separate during cell division because the cell cannot properly assemble the structures responsible for chromosome movement. Which cytoskeletal component is affected?
What are microtubules?
A signaling pathway begins when adrenaline binds to a membrane receptor and ends with the activation of a target gene. Identify the receptor type and the second messenger involved.
What are a G-protein-coupled receptor (GPCR) and cyclic AMP (cAMP)?